234 CLASS MAMMALIA. 



a full-toned sound, of which a, sounded broad, and pa, may 

 convey an idea. It seldom quits its retreat but at night, 

 and then generally in company, without going any great 

 distance from the water. It is a bad runner, and to avoid 

 danger, generally has recourse to diving, rising again to 

 the surface at a very considerable distance from the spot 

 where it first plunges, and continuing for a very long pe- 

 riod under water ; its flesh is good, and the Spanish Ame- 

 ricans eat it on fast or meagre days. It is of a tranquil, 

 gentle disposition, and neither seeks to injure nor quarrel 

 with other animals, is easily tamed, answers to a call, and 

 willingly follows those it knows. The female produces, in 

 general, four or five at a time, on a bed of dry grass, fyc. 

 They are said to live in families, and never quit the vicinity 

 of where they are born. They are common in all the lower 

 parts of South America. 



The genus Cobaya or Anoema of F. Cuvier, is one of 

 those, which, until quite lately, comprehended but a single 

 species ; the existence of a second, however, has been 

 recently indicated. How far the few species which come 

 at the end of this order may require the several generic 

 appropriations into which we see them separated, whereby 

 the larger and more important divisions of zoology are ap- 

 plied to very limited purposes, we shall not even hazard an 

 opinion. 



The oft-repeated difficulty on the subject of distinct spe- 

 cies or of varieties, occurs in this limited genus. Organic 

 affinity would identify the Wild Aperea, which we shall first 

 slightly notice, with the menial Guinea-pig ; superficial dis- 

 similarity, however, would unhesitatingly separate them 

 into distinct species. 



The characters which distinguish this division as a genus 

 will be found sufficiently noticed in the text and table ; the 



